Firefox add-ons – foxmarks, clipmarks

The Foxmarks Bookmark Synchronizer automatically synchronizes your
bookmarks between two or more computers running Firefox. It also lets
you access your bookmarks from any computer anytime via
my.foxmarks.com. An easy-to-use wizard guides you through the quick
startup process. Then Foxmarks works silently in the background to keep
your bookmarks up-to-date on all your computers.